The present invention relates to liquid cleaning compositions.
Liquid cleaning compositions are used more widely than non-liquid cleaning compositions, such as granules, pastes, gels, and mulls. Consumers favor liquid cleaning compositions for convenience and appearance. Liquid cleaning compositions are easily measurable, readily dissolvable in water, and are capable of being applied to heavily stained areas in concentrated solution for pre-treatment. Furthermore, a clear or opaque liquid with a particular color is aesthetically appealing to consumers. In addition, liquid cleaning compositions can incorporate many performance enhancing ingredients that cannot withstand dry operation while eliminating certain environmentally hazardous ingredients, such as phosphate builder.
Although enzymes are one key to improved detergent efficiency, the amount of enzyme in a detergent is limited by a variety of factors. Particularly, it is seen that with higher concentrations comes an increased rate of enzyme self-annihilation. The enzymes' basic nature to break down proteins causes it to split other enzymes at higher detergent concentrations.
The foregoing, and the fact that these enzymes are rather expensive, has forced conventional liquid cleaning compositions to have enzyme concentrations down around 10% to minimize the self-annihilation and cost. However, this not only lowers detergent effectiveness, but also decreases the shelf life of the product due to the gradual loss of enzyme concentration as the enzyme concentration deteriorates.
In an effort to overcome the foregoing problems, expensive chemicals have been added to solutions in an effort to stabilize the enzymes by reducing deterioration seen after production. However, adding such chemicals increases the product price. This technique also further dilutes the solution, thus requiring a larger dosage of the detergent for a given cleaning job. Moreover, the dilution directly increases the cost of packaging and shipping due to more energy use and handling efforts.
Thus, there is a strong need for a liquid cleaning composition that is effective even though packaged in a concentrated form. There is also a strong and unmet need for such a liquid composition that has improved enzyme stability. Moreover, there is also a need for a liquid composition that is more environmentally friendly.